This invention concerns an exercise aid device which allows each individual to perform, safely and comfortably, an appropriate level of aerobic exercise without requiring the use of any special equipment, as well as an exercise aid method employing the same.
The following types of the prior art already exist today in the field of exercise aid devices used for aerobic exercise.
(a) There are now devices (for example, Omron""s HR series heart rate monitors) that use a wristwatch-type monitor to inform the wearer (via a beep or an LCD display) when his heart rate as measured by a heartbeat sensor in a chest belt is in his target zone, which is calculated based on his age.
(b) There are also devices which detect the wearer""s heart rate through a chest belt and feed it back to him via headphones connected to the chest belt (Brand name: Heartalker).
(c) Other devices (for example, Polar""s M series) measure the resting heart rate, calculate the appropriate range (which they call OwnZone(copyright)) based on the heart rate and the person""s age, and emit a beep or some other signal to allow the user to maintain his heart rate in this zone.
(d) There are also wristwatch-type exercise aid devices which detect the pulse wave from the pulse of the user""s finger while he is gradually increasing the intensity of his exercise, analyze this pulse wave, calculate the AT (Anaerobic Threshold) value, and use this value to inform the user as to the intensity which is appropriate for him. (Japanese Patent Publication 9-75491)
(e) Another technique to determine the AT value has the person pedal a stationary bicycle while the load on the pedals is varied so that the level of intensity gradually increases. During this time the person""s heart rate signal or pulse wave signal is detected, and a graph is generated with the heart rate plotted on the horizontal axis and the entropy indicating the fluctuation of the cardiac cycle on the vertical axis. The heart rate corresponding to the lowest point on the graph is then considered to be the AT value. (International Publication: WO99/43392)
(f) Some devices use a photodetector in the person""s external auditory canal to monitor the superficial temporal artery and thereby detect the pulse wave. (Japanese Patent Publication: 7-241279)
(g) Another devices use an optical sensor provided on the person""s front side of finger to detect the pulse wave. In order to detect pulse wave accurately, the output of the optical sensor is subtracted by an output of a motion sensor attached to the person. (Japanese Patent Publication 11-56827)
Three of the aforesaid prior art techniques, (a), (b) and (c), are exercise monitors which use a chest belt. Such monitors are inconvenient in that they require the user to remove some of his clothing each time he wishes to put on the chest belt which contains the heart rate monitor. Also, it is difficult for the person exercising to notice the beep or the display content the wristwatch-type monitor puts out when it receives and processes the signal from the heartbeat sensor in the chest belt.
Wristwatch-type exercise aid devices which detect the pulse wave in the pulse of the person""s finger have two shortcomings. The accuracy with which they detect the pulse wave is inadequate, and it is difficult to communicate the appropriate level of exercise to the person while he is exercising.
Using an indoor stationary bicycle that can determine the AT value limits the exercise to pedaling a bicycle. This is inconvenient, as it does not allow the person to exercise freely out of doors.
And no matter whether the person uses an exercise monitor with a chest belt, a wristwatch-type exercise aid device or an indoor exercise bike, he is liable to find his exercise routine extremely boring. If the user does not inherently want to exercise, because he does not feel comfortable, and he does not feel inclined to exercise rigorously for fitness, he is unlikely to use the device or system for very long.
As is noted on the website of the world-renowned think tank the World Watch Institute, whose address is printed below, obesity and illness caused by insufficient exercise have become a societal problem leading to increased medical costs and lower productivity. While it is true that obesity is caused by insufficient exercise, it could also be said that the spread of television and suburbs designed for automobiles have contributed to the lack of exercise. The details are disclosed in the following site. http://www.worldwatch.org/chairman/issue/001219.html
We need to find ways to address, however slightly, the societal problem of insufficient exercise. As the word xe2x80x9ccouch potatoxe2x80x9d used in the U.S. and Canada suggests, there are a great many people whose lifestyle entails lounging on the couch and eating potato chips while watching rented videos or spending all their time indoors surfing the internet. Obesity is increasing at a high rate among both children and adults. It is a contributing cause of both heart disease and cancer. Because couch potatoes don""t feel like exercising on their own, exercise aid devices must provide enough appeal to get them to want to work out.
For people who do not exercise as a routine part of their daily lives, exercise is not enjoyable. Since they do not enjoy it, they do not continue doing it very long. Music has been used for a long time to motivate and energize people while they are exercising. Many people (more than 40% in our study) wear headphones and listen to music while exercising. After observing at one fitness center seven times in a two-week period, we obtained the following data.
However, not all exercise is good. Too much exercise can be unhealthy. Please refer the following site. http://www.medical-tribune.co.jp/mtbackno3/3317/17hp/M3317421.htm
Appropriate intensity and duration of exercise vary with age, physical strength and level of fitness. No one should exercise if he is sick and is running a temperature. If an elderly person exercises in the same way as a younger person, he may injure his heart, joints or muscles. Furthermore, there are two types of exercise, aerobic and anaerobic. Generally, aerobic exercise is more effective at increasing endurance and reducing body fat, and anaerobic exercise is more effective at increasing muscle strength. The mechanisms which the body uses to generate energy during aerobic and anaerobic exercise are completely different. Immediately after exercise begins, a cycle is put in operation whereby creatine phosphate is broken down to generate energy; however, this cycle lasts only about 40 seconds. Next, the glycolysis cycle goes into effect to generate ATP from glucose and release energy. The glycolysis cycle does not require oxygen, but it generates lactic acid as a product of fatigue. In humans, the accumulation of lactic acid for approximately five minutes will cause the glycolysis cycle to end. What we have described so far is anaerobic exercise. After this point, the TCA cycle uses oxygen to generate ATP from glucose, which makes the exercise aerobic. When the exercise becomes aerobic, glycogen in the muscles is the first energy source tapped. Next, the blood glucose is used. Glycogen from the liver is also used, and subsequently, fat from the fat cells is used. About ten minutes after the start of the exercise, 90% of the reaction process by which aerobic exercise consumes fat has been completed. However, when a person increases the intensity of his exercise too much, his supply of oxygen can become insufficient, which will cause his body to revert to its anaerobic energy scheme, which does not burn body fat. The appropriate range of intensity is one which requires an oxygen intake between 60 and 80% of the maximum intake, depending on the person""s age. The intensity of exercise can also be expressed as pulse rate, with exercise resulting in a rate between 50 and 70% of the maximum considered appropriate. This means that an appropriate level of exercise is one that produces a pulse rate between 50 and 70% of the maximum without exceeding the AT value. A level at 90% of the AT value corresponds to a pulse rate equal to 70% of the maximum rate. Results concerning this equation are given in detail on the following websites. The details are disclosed in the following sites. http://www.geocities.co.jp/Colosseum-Athene/2916/kenshu/training.html http://www02.u-page.so-net.ne.jp/yb3/ki-net/undou.html http://www2.ocn.ne.jp/xcx9cikedama/kiso/at.htm
Thus a level of exercise at 80% of the AT value would translate to a pulse rate equal to 60% of the maximum rate. This would be the midrange of exercise intensity which is both effective and safe.
As the reader may understand from the previous discussion, the type of exercise most effective at burning body fat and eliminating obesity or strengthening the circulatory and respiratory systems and building endurance is aerobic exercise. Aerobic exercise offers a partial solution to the obesity which is proliferating in contemporary society. An exercise aid device is needed which can calculate a target value for each individual""s appropriate intensity of exercise within the aerobic range. This device must also be able to determine both before and during exercise whether the person""s physical condition allows him to exercise. If his condition is such that he should not be exercising, the device must inform him that he should not begin or that he should stop. If his condition allows him to exercise, it must help him to exercise at an intensity level which is safe and appropriate for him. An exercise aid device is needed which will allow anyone, whether he is a couch potato or an avid fitness buff who belongs to a health club, to exercise comfortably and happily and to choose the exercise best suited to his strength and level of fitness. This device should be portable and it should be useable for various kinds of exercise.
The objective of this invention is to provide an exercise aid device which can be used for various kinds of exercise and which enables the user to perform aerobic exercise safely and comfortably at the level best suited to that person, and a system which employs this device.
Means Employed to Solve These Problems
To solve the problems detailed above, the following technical concepts are employed.
1) The level of intensity of aerobic exercise which is most suitable for the person is considered to be 80% of the AT value as determined by analyzing the pulse wave while that person is exercising. The pulse wave is detected by the sensor explained later, and the different type of physiological data is obtained depending on the sensor type, such as pulse wave form, blood velocity form. AT value is obtained by analyzing the forms and the characteristics obtained from these forms. The exercise duration is set between 20-40 minutes according to the general understanding.
2) The user""s physiological data are monitored before and during his workout to determine if it is safe for him to begin and to check intermittently whether he needs to rest. The monitor measures the user""s pulse wave signal, his AT value and his pulse rate, and it uses these values to check his condition before and during his workout.
3) Even people who are less than enthusiastic about exercising, like so-called couch potatoes, will find that they are able to exercise regularly or even daily. Headphones allow sound to be transmitted to the user during the workout to supply him with music, games or instructions, so that his exercise routine will be transformed from a boring obligation to an interesting and enjoyable activity. In addition, this exercise aid device is easier to put on. Instead of being attached to the user""s chest, earlobe or finger as in the prior art, the sensor which detects the pulse wave is placed either in the middle of the user""s ear or behind his earlobe. This location was chosen so that when the user puts on his headphones or earphones, he is also putting on his pulse wave sensor.
4) The pulse rate is measured at the superficial temporal artery, which is near the right ear. The details are disclosed in the following site. http://www.t2star.com/angio/Neuro2.htm
The pulse wave is detected by the following two methods.
(1) Using a Photodetector
The photodetector is placed in external auditory canal of the right ear, and a beam of light is emitted into this artery. Since the proportion of this light which is reflected will vary with the pulse rate, the signal obtained by detecting this reflected light can be considered to represent the pulse rate. In comparison to measuring the pulse rate in the earlobe, measuring it from the superficial temporal artery has a number of benefits. The signal which is obtained is highly accurate and is unlikely to be affected by reflection of nerves, deep breathing or exercise. This method also has the merit that it allows the pulse wave to be measured using a sensor which is built into a set of headphones. However, unless the blood vessel is artificially pressurized, the thickness of the vessel and the density of the blood cells will not vary much with the heart rate, so the AC component of the detected signal (which corresponds to the pulse wave) will be small relative to the DC component.
(2) Using Ultrasound to Measure the Blood Flow
Another method which can be used to measure the pulse in the superficial temporal artery uses ultrasound to measure the blood flow. An ultrasonic wave is transmitted into the artery and the reflected wave is detected. The Doppler effect can then be used to observe the wave form indicating the velocity of the blood flow in the artery. The wave form of the blood flow velocity has a smaller DC component than the signal obtained in method 1 above, so the pulse wave can be detected with greater accuracy.